HOUSTON >> One after the other Monday afternoon, Brandon Crawford and Mike Yastrzemski stuck their legs in the MRI machine at Minute Maid Park, hoping for the best after having their soft tissue tighten up under the stressful playing conditions in Mexico City.

For the most part, they got the results they were hoping for.

The Giants lost more than just their two games at elevation, but their starting shortstop and center fielder, too. Upon arriving in Houston for their three games against the defending World Series champion Houston Astros, Crawford and Yastrzemski were each placed on the injured list.

But after seeing the results of their scans, the Giants’ two key up-the-middle players believed they averted the worst-case scenarios.

Yastrzemski (left hamstring) was diagnosed with a Grade 1 strain, the mildest variety, which seemed unlikely after he felt a “pop” in his hamstring while attempting to make a play on a shallow pop fly in the eighth inning Sunday.

Crawford (right calf), who exited Saturday’s game in the fourth inning, received a Grade “one-plus” diagnosis, which he said was “worse than it feels, I guess, which I think is probably good news.”

“It’s like medium-plus when you’re ordering a steak, I guess, not medium and not medium well,” Crawford added. “It’s maybe a little more than a one but not a two. ... It feels better than (Sunday).”

Crawford was confident that he will not require more than the minimum 10 days on the IL. And while Yastrzemski might be a bit longer, he was moving and feeling better Monday, less than 24 hours after he was gingerly limping around the clubhouse in Mexico City.

“I think that’s a pretty big relief,” manager Gabe Kapler said. “The way Yaz came off the field, obviously you worry you might be without him for a month, six weeks or more, especially with a hamstring that can be so tricky.”

It’s especially good news for a team already strained up the middle of the field.

Their depth problems were only highlighted by the presence of Mauricio Dubón in the opposing dugout.

Since being traded to Houston in a roster crunch last May (he was out of options, and the Giants were out of space on their 26-man roster), the 28-year-old utility man earned a World Series ring and, this season, only recently snapped a 20-game hit streak while filling in for Jose Altuve as the Astros’ second baseman.

At the time, the Giants essentially were left to choose between Dubón and Thairo Estrada, who was also out of options. Estrada, who entered May with the third-best batting average in the National League (.350), will take on shortstop duties in Crawford’s absence, so expect to see a lot of David Villar at second base.

Both players are achieving success a year later, and it’s hard to imagine the Giants wouldn’t like to have Dubón’s versatility and athleticism while navigating the absences of two of their up-the-middle players.

Crawford, who has been texting back-and-forth with Dubón all season, said he was happy for him.

“Obviously, I’m sure the Astros thought they were in a tough spot losing Altuve and he’s stepped up and done awesome for them,” Crawford said. “He had gone 0-for-8 after his 20-game hit streak and was complaining about baseball. Don’t even come to me right now. You just had a 20-game hit streak, guy. Don’t complain about your 0-for-8.”

Kapler recognized the symbolism, but used Dubón as a comparison point for the player expected to receive the bulk of the playing time in Yastrzemski’s absence.

“Interesting that Dubón is in the other dugout today,” Kapler said, “but he’s a nice comp for how quickly he took to center field and became a good quality center fielder for us.”

He was referring to Brett Wisely, who started in center Monday and will share duties there with Cal Stevenson, a Fremont native whom San Francisco acquired from Oakland last week and was recalled from Triple-A Sacramento. Stevenson, who had been designated for assignment by the A’s, profiles as a plus defender in center field, and the Giants have faith in Wisely, who had previously mostly only played second base and shortstop with some brief cameos in left field before this spring.

“I feel pretty good about Wisely’s ability to navigate center field,” Kapler said. “Wise gets good jumps and reads. He’s got a pretty good, strong throwing arm and he’s pretty accurate with it and a solid decision maker.

“Right now, the way we have it set up is Thairo will play mostly shortstop. You could see Villar and Wisely splitting some duties at second base. There may come a time when we want to see Wisely at shortstop as well, but right now the way I’m thinking about it is Thairo at short and Wise/Villar at second base with Wisely and Stevenson handling center field.”

One name that wasn’t initially part of the discussion about center field fill-ins was Austin Slater, who returned from his rehab assignment last week, but still isn’t at full strength.

While Slater remains an option to pinch-hit, the elbow issue that caused him to miss the first two weeks of spring training (before the hamstring strain that cost him the first two weeks of the regular season) continues to limit his throwing ability on defense.

“As soon as we feel like he’s fully capable of doing everything he needs to be a great center fielder, then we can think about Slater as an option as well,” Kapler said.

Sánchez’s future? >> Monday came and went without Gary Sánchez being added to the major-league roster. The 34-year-old catcher, who signed a minor-league deal with the Giants last month, had the ability to opt out of his contract if he wasn’t promoted to the Giants’ roster by the start of May. But, asked Monday, Kapler said he didn’t have anything to report. In 16 games with Sacramento, Sánchez is batting .164 with only one extra-base hit in 55 at-bats.